1. Field of the Invention
The present invention relates to a plasma display panel (PDP) and, more particularly, to a PDP in which a film type filter is coupled with a panel.
2. Description of the Related Art
A PDP is constructed such that discharge cells are formed between a lower substrate with barrier ribs formed thereon and an upper substrate facing the lower substrate, and when an inert gas inside each discharge cell is discharged by a high frequency voltage, vacuum ultraviolet rays are generated to illuminate phosphor to thereby allow displaying of images.
FIG. 1 is a perspective view showing the structure of a related art PDP.
With reference to FIG. 1, in the related art PDP, a scan electrode (Y) and a sustain electrode (Z) are formed on an upper substrate 10, and an address electrode (X) is formed on a lower substrate 18 which faces the upper substrate 10.
The scan electrode (Y) and the sustain electrode (Z) includes a transparent electrodes 12Y and 12Z and metal bus electrodes 13Y and 13Z formed on one edge portion of the transparent electrodes 12Y and 12Z and having a smaller line width than that of the transparent electrodes 12Y and 12Z, respectively.
The transparent electrodes 12Y and 12Z are formed typically with an indium tin oxide (ITO) material on the upper substrate 10. The metal bus electrodes 13Y and 13Z are formed typically with a metal such as chrome (Cr) on the transparent electrodes 12Y and 12Z, respectively, and serve to reduce a voltage drop by the transparent electrodes 12Y and 12Z.
A dielectric layer 14 and a protective film 16 are sequentially stacked to cover the scan electrode (Y) and the sustain electrode (Z) on the upper substrate. Wall charges generated during a plasma discharge are accumulated in the upper dielectric layer 14. The protective film 16 prevents a damage of the dielectric layer 14 and improves the emission efficiency of secondary electrons. The protective film 16 is typically made of magnesium oxide (MgO).
A lower dielectric layer 22 and barrier ribs 24 are formed on the lower substrate 18 on which the address electrode (X) has been formed, and phosphor 26 is coated on the surface of the lower dielectric layer 22 and the barrier ribs 24.
The phosphor layer 26 is excited by ultraviolet rays generated during the plasma discharge to generate one of red, green and blue visible light, and an inert mixture gas is injected into a discharge space formed between the upper substrate 10 and the barrier ribs 24 of the lower substrate 18.
The panel formed by coupling the upper substrate 10 and the lower substrate 18 is a load having enormous capacitance, and when a high voltage driving pulse is applied to the panel capacitor, electromagnetic waves radiate to a front surface thereof. Thus, in order to block the electromagnetic waves, a filter 30 is coupled on the front surface of the panel.
FIG. 2 is a sectional view showing one side of the related art PDP. With reference to FIG. 2, the related art PDP includes a panel 32, a filter 30 coupled to the panel 32, a heat sink plate 34, a PCB (Printed Circuit Board) 36, a back cover 38, a filter supporter 40, and a support member 42.
The panel 32 is formed as the upper substrate 10 and the lower substrate 18 are attached. The filter 30 is installed on the front surface of the panel 32 and the heat sink plate 34 is installed on a rear surface of the panel 32 to sink heat generated from the panel 32 and the PCB 36.
The PCB 36 is attached on the heat sink plate 34 and supplies a drive pulse to the electrodes of the panel 32. The back cover 38 forms an outer appearance of the rear surface of the panel 32 and blocks electromagnetic waves discharged to the rear surface of the panel 32.
The filter supporter 40 connects the filter 30 and the back cover 38 to make the filter 30 grounded, and the support member 42 is installed between the filter 30 and the back cover 38 and covers the filter supporter 40.
FIG. 3 shows the structure of the filter 30 coupled with the panel 32.
With reference to FIG. 3, the related art filter 30 is formed by stacking an antireflection coating film 50, a optical characteristic film 52, glass 54, an electromagnetic interference (EMI) shielding film 56, and a near infrared (NIR) shielding film 58. Though not shown, an attachment layer is formed between respective films to attach the films to each other.
The antireflection coating film 50 prevents reflection of incident light to thereby enhance a optical and shade ratio of the panel 32, and the optical characteristic film 52 controls color temperature of light radiated by the panel 32 to thereby improve optical characteristics of the PDP.
The glass 54 prevents the filter 30 from being damaged by an external impact, and the EMI shielding film 56 prevents EMI made to the front surface of optical the panel 32.
However, the thusly constructed filter 30 of the related art has a problem in that since it includes the glass 54, the weight and thickness of the filter are increased to accordingly increase a fabrication cost.
In addition, the EMI shielding film 56 is made of a transparent conductive metal, so in this case, a metal film needs to be additionally formed to compensate resistance characteristics of the transparent conductive metal. This results in that optical transmittance of the panel is degraded due to the metal film and the fabrication cost of the panel is increased due to the stacking of the metal film.